1. Field of the Invention
This invention is for a safety latch designed to hold a folding pole trailer in its stationary or folded position when traveling on a highway. This invention also has other applications for securely holding other poles or devices that need to be secured while being transported from one location to another.
2. Description of the Prior Art
Pulling, carrying or otherwise transporting a folding pole trailer, or any other vehicle with a longitudinal member, entails certain safety risks. It is not uncommon for the trailer to detach from the cab or truck carrying or pulling the vehicle, thereby creating a road hazard. Detachment can be caused by riding over bumps or potholes in the road or by sudden braking. The detachment of the vehicle or device being transported can result in a serious accident leading to the death and injury of other motorists on the road.
There have been a number of attempts to overcome this problem. U.S. Pat. No. 3,863,329 (Ross) is for an attachment for a pole trailer for facilitating loading of the trailer on the bed of a truck. The attachment includes a length of wire rope bent to a U-shape and maintained so by a bridging piece connecting its free ends. The rope is secured to the pole trailer by means of clamps which engage the rope and maintain the rope in a normal upright position.
U.S. Pat. No. 4,161,329 (Pilz) is for a tractor to trailer connection system in which the tractor is provided with auxiliary trailer attachment or guide means on the rear end of the chassis frame . The trailer guide means is comprised of a cooperating pair of elongated guide plates or guide rail members which are movably mounted on the chassis frame for positioning either in a raised upright operative position or in a lowered inoperative position. The raised guide rails form the ways of a guideway within which the two parallel side beams of the trailer underframe have a snug sliding interfit to firmly lock the tractor chassis frame and trailer underframe together in the horizontal plane thereof as a single rigid unitary frame assembly.
U.S. Pat. No. 4,148,497 (Genty) is for a device for lifting the pole of a trailer of the semi-carried type and coupling the trailer to a tractor vehicle. The device is comprised of a supporting bracket secured beneath and at the rear of the tractor in alignment with the center line thereof, a lever having a hook portion adapted to pick up the shackle of the trailer pole and a crosshead-shaped opposite end, the lever being pivoted to the bracket about a horizontal axis in order to move the hook portion by means of a hydraulic actuator from a low shackle picking-up position to a high coupling and hauling position. The lever is locked by a safety system releasable by manual, electrical or electromagnetic, or hydraulic means.
These devices hinder but do not prevent the unwanted decoupling of the trailer from the attachment device due to road hazards and emergencies. They are also primarily limited to the attachment of a trailer to a cab or tractor type vehicle.